This invention relates to a joint between two members and to a gasket for sealing such joint in which the gasket includes a part of relatively rigid material and other parts of elastomeric or other relatively deformable material. Typical gaskets of this general type, and joints utilizing the same, are disclosed, for example, in U.S. Pat. No. 2,717,793 of Nenzell issued Sept. 13, 1955; U.S. Pat. No. 3,664,676 of Peterson issued May 23, 1972; and U.S. Pat. No. 3,721,452 of Black issued Mar. 20, 1973. Typically, the rigid material of the gasket is utilized for supporting the elastomeric material and for being engaged by the members being sealed so as to limit the compression that may be placed upon the elastomeric portion of the seal by the members. It is also desirable that the elastomeric material be backed up by either the rigid portion of the gasket or by portions of the members so as to prevent extrusion of the elastomeric material from the joint when subjected to high fluid pressure. This frequently involves crushing of the rigid portion of the gasket so as to render reuse doubtful or impossible. In other instances, it requires special gasket configurations that are difficult and expensive to manufacture.
In many cases, it is desirable to have a gasket of special configuration for sealing more than one fluid passage in the members to be sealed, as for example in U.S. Pat. No. 3,664,676 wherein a single gasket assembly seals a number of fluid passages between the cylinder block and cylinder head of an internal combustion engine. In such cases it is desirable to use a single plate of rigid material for supporting a number of elastomeric sealing elements for sealing the various fluid passages. However, in this patent the rigid plate for supporting the elastomeric gaskets does not provide backup support for the elastomeric material and there are separate backup members provided to cooperate with separate elastomeric sealing members at each fluid passage.